DISTINCT count(*), possible?

Greetings,

Can someone tell me how I can get this to work?

select DISTINCT count(address1) from aro;

returns 240, which is wrong.  But this:

select DISTINCT address1 from aro;

returns 219, which is exactally what I am looking for, minus the query
output.  I don't need the tuples, just a count of distinct addresses.

Thanks,
Matthew